Self-propelling cleaner

ABSTRACT

A side wall  51  provided with a coupling hole  50  coupled to the dust transporting pipe  6  of a dust chamber  5  is configured in a sloped shape so as to have a predetermined angle θ with respect to the bottom surface of the dust chamber. A photo detector  14  having a light receiving surface along the surface  51  is disposed near the coupling hole  50  of the side wall  51 . A photo diode  15  for irradiating light toward the photo detector  14  is disposed on the upper surface of the dust chamber  5 . When dust is filled within the dust chamber  5 , since dust is accumulated on the photo detector  14 , the photo detector  14  does not outputs a light detection signal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a self-propelling cleaner which performs cleaning while automatically propelling in a cleaning range.

2. Description of the Related Art

A self-propelling cleaner includes a propelling unit for propelling a main body thereof and a cleaning unit for performing cleaning and performs cleaning while automatically propelling in a cleaning range set in advance.

FIG. 8 is a diagram showing the schematic configuration of a conventional self-propelling cleaner.

As shown in FIG. 8, the conventional self-propelling cleaner is provided in a main body 1 with driving wheels 2, driven wheels 8, and further provided with a nozzle 4 having a brush 40 which contacts with the floor surface and rolls up dust on the floor surface, a dust chamber 5 for accommodating dust thus rolled up by the nozzle 4, and a dust transporting pipe 6 for introducing dust from the nozzle 4 to the dust chamber 5. The self-propelling cleaner includes a propelling control unit 11 for controlling a driving motor 16 for driving the driving wheels 2 to propel the main body 1 along a predetermined route within a cleaning region set in advance, a cleaning control unit 12 for performing the control relating to the cleaning such as the operation control of the brush 40, and a control unit 10 for controlling the entire operation of the cleaner.

Such a conventional self-propelling cleaner is provided with a dust detection unit 13 for detecting an amount of dust within the dust chamber 5. The dust detection unit 13 detects an amount of dust within the dust chamber 5 by using a pressure sensor, an air flow sensor, a reflection type sensor etc. When the dust chamber 5 is filled with dust, the propelling operation and the cleaning operation are stopped and a dust full state is notified to a user by giving a sound or light alarm etc. Conventional self-propelling cleaners as configured as above are disclosed in: JP-A-2003-061882; JP-A-3-173521; JP-A-6-022889; and JP-A-2002-306387.

SUMMARY OF THE INVENTION

However, according to the aforesaid conventional dust detection unit, it is not easy to accurately detect an amount of dust within the dust chamber. For example, in the case of using the pressure sensor or the air flow sensor, different pressures or different air flow rates are observed depending on the states of the floor surface being cleaned even when an amount of dust within the dust chamber is the same. Thus, the detected amount of dust is required to be corrected in accordance with the state of the floor surface being cleaned in order to accurately detect the amount of dust within the dust chamber. Alternatively, in the case of using the reflection type sensor, it is determined that there is no dust within the dust chamber when light emitted from a light emitting portion into the dust chamber is not received by a light receiving portion, whilst it is determined that the dust chamber is filled with dust when the light receiving portion receives the light. However, since an amount of reflection light changes depending on the kind of dust accumulated within the dust chamber and so an amount of light received by the light receiving portion also changes, a dust full state cannot be determined easily.

When it is determined that dust is in a full state, the propelling operation and the cleaning operation are stopped and an alarm is issued by using light or sound, as described above. However, when the operation is stopped, it is difficult to determine whether the operation is stopped due to a failure or due to the termination of the cleaning operation. Further, in the case of the light alarm, since a small-sized light emitting element such as an LED is used as the light emitting portion, it is difficult for a user to recognize the alarm. Furthermore, in the case of the sound alarm, such an alarm cannot be used at the time of cleaning an area where a silent state is required to be kept.

Accordingly, one of objects of the invention is to provide a self-propelling cleaner which can surely detect a dust full state within a dust chamber irrespective of kinds of dust and surely notify dust full information to a user.

According to a first aspect of the invention, there is provided a self-propelling cleaner including: a main body; a cleaning unit that accommodates dust taken from a cleaning nozzle through a dust transporting pipe within a dust chamber; a propelling unit that propels and turnarounds the main body; a propelling control unit that controls the propelling unit to move the main body within a predetermined region; and a dust amount detection unit that detects an amount of dust accommodated within the dust chamber, the dust amount detection unit including a light detector that detects light introduced within the dust chamber to detect the amount of dust, wherein one side wall of the dust chamber having a coupling hole coupled to the dust transporting pipe is formed in a sloped shape, wherein the light detector is disposed at a position near the coupling hole of the side wall, wherein a plurality of the light detector are disposed at different positions in a vertical direction of the side wall, wherein the propelling control unit controls the propelling unit to perform a propelling and circling movement different from a movement at a normal cleaning operation when the dust amount detection unit detects that dust is filled within the dust chamber.

According to a second aspect of the invention, there is provided a self-propelling cleaner including: a main body; a cleaning unit that accommodates dust taken from a cleaning nozzle through a dust transporting pipe within a dust chamber; a propelling unit that propels and turnarounds the main body; a propelling control unit that controls the propelling unit to move the main body within a predetermined region; and a dust amount detection unit that detects an amount of dust accommodated within the dust chamber, the dust amount detection unit including a light detector that detects light introduced within the dust chamber to detect the amount of dust, wherein one side wall of the dust chamber having a coupling hole coupled to the dust transporting pipe is formed in a sloped shape, and wherein the light detector is disposed at a position near the coupling hole of the side wall.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and advantages of the present invention will become more apparent by describing preferred exemplary embodiments thereof in detail with reference to the accompanying drawings, wherein:

FIGS. 1A and 1B are block diagrams showing a schematic configuration of the self-propelling cleaner according to a first embodiment and an enlarged sectional diagram showing a dust chamber 5;

FIGS. 2A and 2B are enlarged sectional diagrams showing different dust accumulating states within the dust chamber 5 shown in FIGS. 1A and 1B;

FIG. 3 is a flow chart showing the operation at the time of the propelling and cleaning operation of the self-propelling cleaner according to the first embodiment;

FIG. 4 is a plan view showing a range and a route in and along which the self-propelling cleaner propels;

FIGS. 5A and 5B are side views showing schematic configurations near the dust chamber of the self-propelling cleaner according to a second embodiment;

FIGS. 6A-6C are side views showing schematic configurations near the dust chamber of the self-propelling cleaner according to a third embodiment;

FIGS. 7A-7C are side views showing schematic configurations near the dust chamber of the self-propelling cleaner according to a fourth embodiment;

FIG. 8 is a block diagram showing the schematic configuration of a conventional self-propelling cleaner.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the accompanying drawings, a description will be given in detail of preferred embodiments of the invention.

A self-propelling cleaner according to the first embodiment of the invention will be explained with reference to drawings. In the embodiment, the explanation will be made as to a self-propelling cleaner of a strike-up type which strikes dust up by a brush within a nozzle and accommodates the dust thus struck-up within a dust chamber.

FIG. 1A is a block diagram showing the schematic configuration of the self-propelling cleaner according to this embodiment, and FIG. 1B is an enlarged sectional diagram showing a dust chamber 5.

The self-propelling cleaner is configured by a propelling control unit and a propelling unit for propelling a main body 1 along a route within a cleaning region set in advance, and a cleaning unit for removing dust on the floor surface within the cleaning region and accommodating the dust therein.

Driving wheels 2 and driving motors 16 coupled to the driving wheels 2 to rote the driving wheels 2 are provided at the left and right portions of the lower portion at the rear side of the main body 1, respectively. A driven wheel 3 is provided at the lower portion of the front side of the main body 1. The driving wheels 2, the driving motors 16 and the driven wheel 3 correspond to “the propelling unit” according to the invention. A driving motor 16 is coupled to a propelling control unit 11.

The main body 1 is provided, at the lower portion of the front side thereof, with a nozzle 4 for removing dust on the floor surface, a box-shaped dust chamber 5 for accommodating dust therein, and a dust transporting pipe 6 for coupling the nozzle 4 to the dust chamber 5 to conduct dust into the dust chamber 5. A brush 40 is disposed within the nozzle 4. The main body 1 is provided with a cleaning control unit 12 for controlling the cleaning operation. The nozzle 4, the brush 40, the dust chamber 5, the dust transporting pipe 6 and the cleaning control unit 12 correspond to “a cleaning unit” according to the invention.

As shown in FIG. 1B, a coupling hole 50 coupled to the dust transporting pipe 6 is formed at a portion near the upper end of the side wall 51 of the dust chamber 5. The side wall 51 is configured in a sloped shape with respect to the bottom surface thereof, that is, configured in a manner that an angle θ between the bottom surface and the inner surface of the side wall 51 forms an obtuse angle larger than 90 degrees. The remaining side walls of the dust chamber are configured so as to be orthogonal to the bottom surface. When the dust chamber is configured in this manner, even when dust reached within the dust chamber 5 from the coupling hole 50 is placed on the surface of the side wall 51, the dust slips down the slope in the bottom surface direction and so accumulated sequentially from the bottom surface side. A photo detector 14 having a light receiving surface in parallel to the side wall 51 is provided neat the coupling hole 50 of the side wall 51. A photo diode 15 for irradiating light toward the photo detector 14 is provided near the coupling hole 50 on the upper surface of the dust chamber 5.

The photo diode 15 and the photo detector 14 are coupled to a control unit 10 for controlling the entirety of the cleaner including the propelling control unit 11 and the cleaning control unit 12. When the photo detector 14 cannot receive light emitted from the photo diode 15, it is detected that the dust chamber 5 is filled with dust. The photo diode 15 and the photo detector 14 correspond to “a dust amount detection unit” according to the invention.

Next, the explanation will be made as to the normal cleaning operation of such a self-propelling cleaner.

When a user inputs a cleaning start instruction or a cleaning start time set in advance is detected, the cleaning control unit 12 rotates the brush 40 to strike up dust on the floor surface thereby to introduce the dust within the nozzle 4. The dust introduced within the nozzle 4 is accommodated into the dust chamber 5 through the dust transporting pipe 6.

The propelling control unit 11 controls the driving motors 16 to rotate the driving wheels 2 thereby to start the propelling operation from a cleaning start position. In this case, a not-shown memory stores the propelling route of the main body 1 in advance. For example, in an example shown in FIG. 4, the main body propels along the long side of a rectangular cleaning region (an approach route), then makes a right-angle turn in the direction along the short side of the cleaning region when the main body reaches the boundary of the cleaning region and propels by a predetermined distance along the short side. Next, the main body makes a right-angle turn in the direction along the long side and propels along the long side in the direction opposite to the approach route. Then, the main body makes a right-angle turn in the direction along the short side and propels by the predetermined distance. Hereinafter, the aforesaid procedures are repeated. In general, this route is called a zigzag propelling route. The propelling control unit 11 controls the driving motors 16 so that the main body propels along this route, whereby the driving motors 16 rotate in the predetermined directions in accordance with the control of the propelling control unit. Not-shown plurality of sensors are attached to the main body 1. These sensors detect the circumstance in the periphery of the main body 1. The detection results of the sensors are inputted into the propelling control unit 11. Then, the propelling control unit 11 drives the driving motors 16 in accordance with the detection results thereby to prevent the main body from colliding with an obstacle and a wall at the periphery thereof.

Light is emitted continuously or at a predetermined period from the photo diode 15 toward the photo detector 14 while the main body propels and cleans in the aforesaid manner. When the photo detector 14 receives the light, the photo detector generates a detection signal to output it to the control unit 10. Then, the control unit 10 recognizes in response to the detection signal that the dust chamber 5 is not filled with dust and so controls the cleaning control unit 12 and the propelling control unit 11 so as to continue the cleaning operation while continuing the propelling operation.

When the cleaning of the region set in advance is completed, the cleaning control unit 12 stops the rotation of the brush 40 thereby to stop the cleaning operation. On the other hand, the propelling control unit 11 stops the propelling operation at this time or continuously drives the driving motors 16 to move the main body to a predetermined standby position (for example, a charging position or the cleaning start position).

Next, the explanation will be made with reference to FIGS. 2A to 4 as to the operation when the dust chamber 5 is filled with dust during the cleaning operation.

FIGS. 2A and 2B are enlarged sectional diagrams of the dust chamber 5, wherein FIG. 2A shows a case where an amount of dust accumulated is small, and FIG. 2B shows a case where the dust chamber is filled with dust.

FIG. 3 is a flowchart at the time of the propelling and cleaning operation. FIG. 4 is a plan view showing a region, a route and a locus where the self-propelling cleaner propels.

As described above, when the cleaning operation and the propelling operation are started (S1 to S2), the photo diode 15 emits light in accordance with the voltage applied from the control unit 10. In this case, as shown in FIG. 2A, when an mount of dust 100 within the dust chamber 5 is small, dust placed on the surface of the side wall 51 moves to the bottom surface side as described above. Thus, since there is no dust on the photo detector 14, the photo detector receives light emitted from the photo diode 15. When the photo detector 14 receives light, the photo detector outputs the detection signal to the control unit 10. The control unit 10 recognizes the detection signal thereby to detect that the dust chamber 5 is not filled with dust 100 (S3) and outputs an instruction for continuing the cleaning operation and the propelling operation to the propelling control unit 11 and the cleaning control unit 12. On the other hand, as shown in FIG. 2(b), when the dust chamber 5 is filled with dust 100, since dust also exists on the photo detector 14, the photo detector 14 cannot receive light emitted from the photo diode 15. Thus, the photo detector 14 does not generate the detection signal nor apply it to the control unit 10. Since the control unit 10 cannot detect the detection signal, the control unit 10 detects that the dust chamber 5 is filled with dust 100 (S3). When the control unit 10 detects the dust full state, the control unit outputs an instruction for stopping the cleaning due to the dust full state to the propelling control unit 11 and the cleaning control unit 12. In accordance with this instruction, the cleaning control unit 12 stops the operation of the brush 40 to stop the cleaning operation and also the propelling control unit 11 stops the operation of the driving motors 16 (S4). Next, after the control unit 10 confirms that the cleaning operation has stopped, the control unit outputs to the propelling control unit 11 an instruction for starting a special movement at the time of the dust full state. In accordance with this instruction, the propelling control unit 11 controls the left and right driving motors 16 so as to perform a special movement stored in advance, that is, to circle for a predetermined number of times with a predetermined radius at the position where the dust full state is detected, for example, as shown in FIG. 4. Thus, in accordance with this instruction, the right driving motor 16 rotates at the speed higher than that of the left driving motor 16, whereby the main body 1 continuously circles counterclockwise. Since such an operation does not appear in the normal cleaning operation, a user can know that the dust chamber 5 is filled with dust when the user sees this circling operation. Thus, the user takes the dust chamber 5 out of the main body 1, then throws out the dust 100 within the dust chamber 5 and attaches the dust chamber within the main body 1 again. At this time, since the dust on the photo detector 14 is removed, the photo detector 14 generates and outputs the detection signal to the control unit 10. The control unit 10 determines that the dust within the dust chamber 5 is removed (not in the dust full state) in accordance with the detection signal and so outputs control instructions for performing the normal cleaning operation again to the propelling control unit 11 and the cleaning control unit 12. In accordance with these instructions, the cleaning control unit 12 starts the brush 40 to rotate again and the propelling control unit 11 controls the driving motors 16 so as to propel the main body along the route of the non-cleaned region.

Since the embodiment is configured in the aforesaid manner, dust is placed on the photo detector provided on the side wall of the dust chamber only when dust is filled within the dust chamber thereby to interrupt the light reception, so that the dust full state can be detected surely. Further, since transmission light is employed for the detection, amount of light to be detected does not change depending on the kinds of dust, so that the dust full state can be detected surely irrespective of the kinds of dust. Furthermore, since the light receiving surface of the photo detector is inclined upward, the photo detector can receive light from the upper direction of the dust chamber and also light from the side surface opposing to the side surface where the photo detector is provided. Thus, the attachment position of the photo detector can be selected from the wide area. In particular, since the photo diode can be attached to the upper surface side where the photo diode can be attached relatively with ease, the self-propelling cleaner having the aforesaid effects can be realized with the simple configuration. Furthermore, since the light receiving surface of the photo detector is inclined upward, the dust full state can be detected surely even when a window for introducing external light into the dust chamber is provided at the upper surface of the dust chamber in place of the photo diode. Thus, the self-propelling cleaner having the aforesaid effects can be realized with the further simple configuration.

Further, since the embodiment is configured in the aforesaid manner, a user can easily and surely recognize that the dust chamber is filled with dust by seeing the movement of the main body. Further, since the dust full state is notified by the movement of the main body, the dust full state can be notified in a wider range as compared with the case of notifying the dust full state by a small-sized light emitting element such as an LED. Furthermore, since the dust full state is notified only by the movement of the main body, even when the cleaner is used in an environment requiring silence (for example, a room where a baby exists), the dust full state can be notified surely without disturbing the silent environment. In this manner, when the aforesaid configuration of the embodiment is employed, even when a user exists at a position relatively away from the cleaner, the dust full state of the dust chamber can be notified surely to the user without influencing on the utilizing environment.

Next, the self-propelling cleaner according to the second embodiment will be explained with reference to FIGS. 5A and 5B. In this embodiment, the explanation will be made as to a self-propelling cleaner of a vacuum type which is provided with an evacuation fan at the dust chamber.

FIGS. 5A and 5B are side views showing the schematic configurations near the dust chamber of the self-propelling cleaner according to this embodiment, wherein FIG. 5A shows a state where an amount of dust accumulated within a dust chamber 5 is small, and FIG. 5B shows a state where the dust chamber 5 is filled with dust.

The self-propelling cleaner shown in FIGS. 5A and 5B includes an evacuation fan 21 on a side wall 52 opposing to a side wall 51 having a coupling hole 50 coupled to a dust transporting pipe 6 within the dust chamber 5. The evacuation fan 21 is driven by a fanmotor 22. The fan motor 22 is controlled in its operation by a cleaning control unit 12. The remaining configuration of this embodiment is same as the self-propelling cleaner shown in FIG. 1.

Since this embodiment is configured in the aforesaid manner, dust is accumulated within the dust chamber 5 as shown in FIGS. 5A and 5B, that is, dust is gradually accumulated on the bottom surface closer to the side wall 52 side provided with the evacuation fan 21. Even in such an accumulation state of the dust, since the operation of the photo detector 14 is same as that of the first embodiment, this embodiment can obtain the same effects as those of the first embodiment. Further, since dust on a floor is forcedly sucked by using the evacuation fan 21, the cleaning is performed further cleanly as compared with the first embodiment.

Next, the self-propelling cleaner according to the third embodiment will be explained with reference to FIGS. 6A-6C.

FIGS. 6A-6C are side views showing the schematic configurations near the dust chamber of the self-propelling cleaner according to this embodiment, wherein FIG. 6A shows a state where an amount of dust accumulated within a dust chamber 5 is small, FIG. 6B shows a state where an amount of dust accumulated within the dust chamber 5 is close to full, and FIG. 6C shows a state where the dust chamber 5 is filled with dust.

The self-propelling cleaner shown in FIGS. 6A-6C is configured in a manner that photo detectors 14 a, 14 b are attached to different vertical positions on the side wall 51 of the dust chamber 5, and photo diodes 15 a, 15 b for irradiating lights toward the photo detectors 14 a, 14 b are provided on the upper surface of the dust chamber 5, respectively. The remaining configuration of this embodiment is same as the self-propelling cleaner shown in FIG. 1. The photo detector 14 a is provided near the coupling hole 50 of the side wall 51 like the photo detector 14 in FIG. 1. The photo detector 14 b is disposed in adjacent to the photo detector 14 a at a position below the photo detector 14 a by a predetermined distance.

Since this embodiment is configured in this manner, in a state where an accumulated amount of dust is small, both the photo detectors 14 a, 14 b can receive light and so a control unit 10 can detect that an amount of dust accumulated within the dust chamber 5 is small. Next, when dust is accumulated gradually, firstly the photo detector 14 a becomes unable to receive light from the photo diode and the control unit 10 detects this fact. In this case, since the photo detector 14 b is disposed in adjacent to the photo detector 14 a at the position below the photo detector 14 a by the predetermined distance, the photo detector 14 a shortly becomes also unable to receive light from the photo diode. That is, this fact means that an amount of dust is closing to the full state. When the control unit 10 detects this state, the control unit issues to a user information representing that dust will be full soon. As the information issuing method, although it is possible to use light or sound, for example, a movement different from the aforesaid special movement at the time of the dust full state may be performed temporarily. Then, the cleaning operation is continued, and when the dust chamber is filled with dust, the diode 14 a also becomes unable to receive light from the photo diode. Thus, the aforesaid operation of notifying the dust full state is performed.

According to the aforesaid configuration, a user can know in advance that the dust chamber will be soon filled with dust. That is, in this manner, a user can obtain information relating to the dust full state twice. Accordingly, a user can recognize the dust full state within the dust chamber further surely. Further, since a user can also throw out dust within the dust chamber in response to the information issued before the dust full state, the user can throw out dust before the dust within the dust chamber becomes full and the cleaning operation is stopped. Thus, it is possible to prevent the waste of cleaning time during the stoppage due to the dust full state. Further, since the special movement differs between the dust full state and the state just before the dust full state, a user can recognize whether the current state is the dust full state or the state just before the dust full state by seeing the movement of the cleaner.

Incidentally, although this embodiment employs two photo detectors, three or more photo detectors may be disposed on the side wall at different vertical positions, in accordance with the required specification.

Further, although the aforesaid embodiment is configured to provide one photo diode for one photo detector, this embodiment may be configured to provide one photo diode for plural photo detectors. In such a configuration, the number of the photo diodes to be disposed can be reduced.

Next, the self-propelling cleaner according to the fourth embodiment will be explained with reference to FIGS. 7A-7C.

FIGS. 7A-7C are side views showing the schematic configurations near the dust chamber of the self-propelling cleaner according to this embodiment, wherein FIG. 7A shows a state where dust is scarcely accumulated within a dust chamber 5, FIG. 7B shows a state where dust is accumulated on one side within the dust chamber, and FIG. 7C shows a state where the dust chamber 5 is filled with dust.

The self-propelling cleaner shown in FIGS. 7A-7C is configured in a manner that each of a side wall 51 provided with the coupling hole 50 of the dust chamber 5 and a side wall 52 opposing thereto is formed in a sloped shape. The side wall 51 is provided with a photo detector 14 a near the coupling hole 50 and the side wall 52 is provided with a photo detector 14 c at the same height as the photo detector 14 a. Photo diodes 15 a, 15 c for respectively emitting lights toward the photo detectors 14 a, 14 c are disposed on the upper surface of the dust chamber 5.

Since this embodiment is configured in the aforesaid manner, in the state where dust does not exist at all within the dust chamber 5 as shown in FIG. 7A, each of the photo detectors 14 a, 14 c can receive light, so that a control unit 10 can detect that dust is scarcely accumulated within the dust chamber 5. Next, when dust is accumulated on the side wall 51 side within the dust chamber, the photo detector 14 a cannot receive light but the photo detector 14 c can receive light. Thus, a detection signal only from the photo detector 14 c is outputted to the control unit 10. The control unit 10 receives this detection signal thereby to detect that dust is accumulated on the one side within the dust chamber 5 and then issues information relating to the one-side accumulation state of dust within the dust chamber 5. When a user receives this information, the user temporarily stops the self-propelling cleaner, then performs an operation such as shaking of the main body thereby to eliminate the one-side accumulation state of dust and restarts the cleaning operation. In this case, the one-side accumulation state of dust may be eliminated by automatically moving the main body like the aforesaid special movement at the time of the dust full state. Then, in the state where the one-side accumulation state of dust is eliminated, the cleaning operation is performed again. When dust is accumulated on the photo detectors 14 a, 14 c as shown in FIG. 7C, each of the photo detectors 14 a, 14 c becomes unable to receive light and so the detection signal is not outputted from the photo detectors. Thus, the control unit 10 discriminates that dust is filled within the dust chamber 5 and so the aforesaid control at the time of the dust full state is performed.

According to such a configuration, the one-side accumulation state of dust within the dust chamber can be confirmed without opening the main body. Further, as the needs arises, a user can throw dust out or eliminate the one-side accumulation state of dust and then start the cleaning operation again. Further, the self-propelling cleaner can be configured which can prevent the erroneous detection of the dust full state due to the one-side accumulation state of dust within the dust chamber and can surely detect the dust full state.

Incidentally, in this embodiment, although the photo detector is disposed on each of the opposing side walls, a plurality of the photo detectors may be disposed on each of the opposing side walls like the third embodiment.

Further, although each of the third and fourth embodiments is configured based on the configuration of the self-propelling cleaner of a strike-up type shown in the first embodiment, the self-propelling cleaner of a vacuum type as shown in the second embodiment may be applied to the configuration shown in each of the third and fourth embodiments.

As described above with reference to the embodiments, according to one aspect of the invention, there is provided a self-propelling cleaner including: a main body; a cleaning unit that accommodates dust taken from a cleaning nozzle through a dust transporting pipe within a dust chamber; a propelling unit that propels and turnarounds the main body; a propelling control unit that controls the propelling unit to move the main body within a predetermined region; and a dust amount detection unit that detects an amount of dust accommodated within the dust chamber, the dust amount detection unit including a light detector that detects light introduced within the dust chamber to detect the amount of dust, wherein one side wall of the dust chamber having a coupling hole coupled to the dust transporting pipe is formed in a sloped shape, and wherein the light detector is disposed at a position near the coupling hole of the side wall.

According to this configuration, dust introduced into the dust chamber sequentially flows on the bottom surface side along the slope-shaped side wall and then accumulated. Thus, when the dust chamber is not filled with dust, dust is not accumulated on the light detector, so that the light detector can receive light within the dust chamber and so it is detected that the dust chamber is not filled with dust. On the other hand, when the dust chamber is filled with dust, dust is accumulated on the light detector, so that the light detector cannot receive light and so it is detected that the dust chamber is filled with dust.

Further, the self-propelling cleaner according to the invention is characterized in that the light detector detects light introduced within the dust chamber from an external-light introducing window provided at the main body.

According to this configuration, when the dust chamber is not filled with dust, light introduced from the external-light introducing window reaches the light detector and then received thereby. On the other hand, when the dust chamber is filled with dust, light introduced from the external-light introducing window does not reach the light detector and so not received thereby, so that the aforesaid dust full state is detected.

Further, the self-propelling cleaner according to the invention is characterized in that a plurality of the light detector are disposed at different vertical positions of the slope-shaped side wall.

According to this configuration, since a plurality of the light detector are provided at the different vertical positions of the side wall by utilizing a fact that dust is gradually accumulated from the bottom surface of the dust chamber, dust detection results representing plural states respectively according to different amounts of dust within the dust chamber can be outputted.

Further, the self-propelling cleaner according to the invention is characterized in that another side wall of the dust chamber opposing to the one side wall having the coupling hole is formed in a sloped shape, and the dust amount detection unit is also provided at the another side wall.

According to this configuration, since the dust amount detection unit is provided at each of the opposed side walls, the one-side accumulation state of dust within the dust chamber can be detected. That is, in the case where the light detector is provided at both the opposed side walls at the same height, when a light receiving element on the side wall of the coupling hole side does not detect light but a light receiving element on the side wall of the opposite side detects light, it can be recognized that accumulated dust is higher on the side of the side wall of the coupling hole side than the side of the side wall of the opposite side and so dust is accumulated on one side.

Further, the self-propelling cleaner according to the invention is characterized in that the propelling control unit controls the propelling unit to perform a propelling and circling movement different from a movement at a normal cleaning operation when the dust amount detection unit detects that dust is filled within the dust chamber.

According to this configuration, when dust is filled within the dust chamber, the main body changes its movement from that at the normal operation and the dust full state of the dust chamber is notified to a user.

According to the self-propelling cleaner as thus configured, since the side wall is formed in a sloped shape, the light detector cannot be shielded from light until dust is accumulated to the height where the light detector is provided. Further, the invention is configured in a manner that the dust amount detection unit is constituted by using a light transmission type sensor including this light detector. Thus, the dust full state within the dust chamber can be surely detected irrespective of kinds of dust.

Further, according to the self-propelling cleaner, external light is introduced as a light irradiated to the light detector, whereby the dust amount detection unit, which can surely detect the dust full state in the aforesaid manner without requiring light emitting unit, can be configured with a simple configuration.

Furthermore, according to the self-propelling cleaner, since a user can recognize an amount of dust within the dust chamber at plural levels, the user can surely recognize information such that dust will be filled soon within the dust chamber as well as the dust full information.

Furthermore, according to the self-propelling cleaner, the dust amount detection unit is provided at each of the opposed side walls. Thus, when the detection results of these dust amount detection unit are compared, the dust full state and the dust accumulation state such as the one-side accumulation state of dust within the dust chamber can be detected further accurately.

Furthermore, according to the self-propelling cleaner, since the main body moves in a manner different from the usual movement in accordance with the dust full state detected by the dust amount detection unit, the dust full state can be surely notified to a user who exists at a position relatively away from the cleaner. Further, the dust full state can be surely notified without being restricted by a peripheral circumstance such as an environment required to be silent.

Although the present invention has been shown and described with reference to a specific preferred embodiment, various changes and modifications will be apparent to those skilled in the art from the teachings herein. Such changes and modifications as are obvious are deemed to come within the spirit, scope and contemplation of the invention as defined in the appended claims. 

1. A self-propelling cleaner comprising: a main body; a cleaning unit that accommodates dust taken from a cleaning nozzle through a dust transporting pipe within a dust chamber; a propelling unit that propels and turnarounds the main body; a propelling control unit that controls the propelling unit to move the main body within a predetermined region; and a dust amount detection unit that detects an amount of dust accommodated within the dust chamber, the dust amount detection unit including a light detector that detects light introduced within the dust chamber to detect the amount of dust, wherein one side wall of the dust chamber having a coupling hole coupled to the dust transporting pipe is formed in a sloped shape, wherein the light detector is disposed at a position near the coupling hole of the side wall, wherein a plurality of the light detector are disposed at different positions in a vertical direction of the side wall, wherein the propelling control unit controls the propelling unit to perform a propelling and circling movement different from a movement at a normal cleaning operation when the dust amount detection unit detects that dust is filled within the dust chamber.
 2. A self-propelling cleaner comprising: a main body; a cleaning unit that accommodates dust taken from a cleaning nozzle through a dust transporting pipe within a dust chamber; a propelling unit that propels and turnarounds the main body; a propelling control unit that controls the propelling unit to move the main body within a predetermined region; and a dust amount detection unit that detects an amount of dust accommodated within the dust chamber, the dust amount detection unit including a light detector that detects light introduced within the dust chamber to detect the amount of dust, wherein one side wall of the dust chamber having a coupling hole coupled to the dust transporting pipe is formed in a sloped shape, and wherein the light detector is disposed at a position near the coupling hole of the side wall.
 3. The self-propelling cleaner according to claim 2, wherein the dust amount detection unit includes a light emitting unit that emits light within the dust chamber towards the light detector.
 4. The self-propelling cleaner according to claim 2, wherein the dust amount detection unit includes an external-light introducing window that is provided at the main body and introduces light into the dust chamber towards the light detector.
 5. The self-propelling cleaner according to claim 2, wherein a plurality of the light detector are disposed at different positions in a vertical direction of the side wall.
 6. The self-propelling cleaner according to claim 2, wherein another side wall of the dust chamber opposing to the one side wall having the coupling hole is formed in a sloped shape, and wherein the dust amount detection unit is provided at both of the one side wall and the another side wall.
 7. The self-propelling cleaner according to claim 2, wherein the propelling control unit controls the propelling unit to perform a propelling and circling movement different from a movement at a normal cleaning operation when the dust amount detection unit detects that dust is filled within the dust chamber. 